Beijing-flavored erhua form of
角 (jué, 'role / character').
角 here is read jué (NOT jiǎo, which means 'horn / corner'). Strongly associated with traditional theater -
大角儿 'big star',
名角儿 'famous lead'. The 2017 film
老炮儿 and Chen Kaige's
霸王别姬 (Farewell My Concubine) are full of this usage.